Table of Contents Author Guidelines Submit a Manuscript
Journal of Nanotechnology
Volume 2011 (2011), Article ID 392754, 6 pages
Research Article

Improving the Hydrophobicity of ZnO by PTFE Incorporation

Council of Scientific and Industrial Research, Surface Engineering Division, National Aerospace Laboratories, Bangalore 560 017, India

Received 7 March 2011; Accepted 24 March 2011

Academic Editor: Mallikarjuna Nadagouda

Copyright © 2011 Meenu Srivastava et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The objective of the present study is to obtain a zinc oxide- (ZnO-) based superhydrophobic surface in a simple and cost-effective manner. Chemical immersion deposition being simple and economical has been adopted to develop modified ZnO coating on glass substrate. Several modifications of ZnO like treatment with alkanoic acid (stearic acid) and fluoroalkylsilane to tune the surface wettability (hydrophobicity) were attempted. The effect of thermal treatment on the hydrophobic performance was also studied. It was observed that thermal treatment at 70°C for 16 hrs followed by immersion in stearic acid resulted in high water contact angle (WCA), that is, a superhydrophobic surface. Thus, a modified ZnO superhydrophobic surface involves the consumption of large amount of electrical energy and time. Hence, the alternate involved the incorporation of low surface energy fluoropolymer polytetrafluoroethylene (PTFE) in the ZnO coating. The immersion deposited ZnO-PTFE composite coating on modification with either stearic acid or fluoroalkylsilane resulted in a better superhydrophobic surface. The coatings were characterized using Scanning Electron Microscope (SEM) for the surface morphology. It was found that microstructure of the coating was influenced by the additives employed. A flower-like morphology comprising of needle-like structure arranged in a radial manner was exhibited by the superhydrophobic coating.